Which word describes harshness or roughness of manner?

The term that describes harshness or roughness of manner is "asperity." This word originates from the Latin "asperitas," which means roughness or bitterness. In a social context, it refers to an abrasive or severe attitude, often marked by a lack of politeness or kindness. When someone displays asperity, they may be sharp-tongued or quick to criticize, creating a sharp contrast to more refined or gentle manners.

Conversely, gentility represents a quality of being genteel or refined, suggesting politeness and social grace. Hostility conveys animosity or antagonism rather than mere harshness, while serenity indicates calmness and tranquility, which are the opposite of roughness. Therefore, "asperity" is the most accurate choice to describe a harsh or rough manner.